invention relates to a key case having a swing-out flat key and a slotted passage opening for the flat key, which passage opening extends continuously over a corner of the key case and an adjoining longitudinal section of a front and side edge of the key case and which merges into a receiving space for the flat key. The flat key has a grip part and a shank part angled approximately perpendicularly thereto and is lowered into its non-working position. The flat key is articulatedly mounted on the key case in an area near to a free end part of its grip and wherein the articulation point lies in an area near to the front edge of the key case and at a lateral distance from both the corner of the key case and the center longitudinal axis of the key case and wherein the shank part of the flat key projects from an approximate center of the front edge of the key case in its swung-out working position.
German Patent Specification No. 2,226,385 discloses a key case of this general type. There the key case forms a turning grip for the key shank when the flat key is swung out. The key case is distinguished by a compact external form of small breadth, as a result of which the flat key is also suitable for actuating sunken locking cylinders. This suitability is further improved by the key-case front edge (located on the insertion side) being shortened to a minimum, while the key case widens trapezoidally with increasing distance from the front edge. To enable the long shank part to be sunk in the widened longitudinal section of the key case, the flat key is articulated on the key case via its grip part, which guides the key shank like an extension arm. In addition, the grip part enables a turning force to be gently transmitted from the key case to the shank part, since, in its working position, it lies in its receiving space in an essentially positive-locking manner and with its entire longitudinal extent between the broad sides of the key case. Thus no excessive bending stability of the key case is necessary.
However, the turning force must be supported between the housing and the key shank almost entirely via the mounting axis of the key shank. This type of support for the turning force requires an exceptionally robust pivot mounting of the key shank in the key case housing as well as corresponding bending rigidity of the key case housing itself.
In addition, since the key shank, in its working position, projects from a longitudinal edge of the housing, its utility, on account of the turning swing associated therewith, is considerably limited. Thus sunk locking cylinders as well as locking-cylinder insertion openings surrounded by raised contours can only be reached by means of an extra-long key shank. However, an extra-long key shank is not desirable either from the points of view of handling or of strength.
The object of the invention is therefore to improve a key case having a swing-out flat key as defined in the first paragraph of this application without occupying much construction space for accommodating the key and by integrating the key into a key case housing which is also a carrier for an additional function.
This object is achieved by having the key case designed as an elongated housing with a key receiving space shaped as a two-legged receiving shaft which, viewed over its length, is essentially L-shaped and extends with its longer leg along the side edge and with its shorter leg along the front edge of the key case housing. A flat key, in its non-working position, is pivoted into a lowered position with its shank part extending into the longer L-shaped leg and with its grip part into a longitudinal area of the shorter L-shaped leg and near the corner of the key case housing. The shank part of the key can be pivoted outward of the housing around its corner through which the flat key passes into a working position pointed in the opposite direction from its lowered non-working position and whereupon the grip part of the key also is pivoted into a longitudinal area of the shorter leg more remote from the corner than the pivot point. By this construction it is possible to reduce the length of the front edge on the operating side of the housing to a size which corresponds to the diameter of conventional locking cylinders. In combination with a slim, rectangular key shaped housing of the same breadth, mechanical lock operation by means of the swung-out flat key is thus possible both in sunken locking cylinders and in locking cylinders surrounded by raised contours.
The flat key, in its non-working position, is preferably sunk in the receiving shaft area in such a way that the key edges are flush with the key housing and as a result of which, key grooves are protected from dirt. Damaging or dirtying of key case receptacles such as clothes pockets, handbags or the like, by parts of the flat key which protrude from the key case is thus reliably avoided. The bottom of the receiving shaft, which at the same time forms the allocated boundary wall of the key case housing, can be used to limit the swing-in or swing-out throw of the flat key. To this end, the depth of the lateral leg of the receiving shaft must correspond to the breadth of the shank part, and the depth of the front leg must correspond to the breadth of the grip part.
However, in the front leg of the receiving shaft, this depth is only sufficient if it provides the necessary pivoting space for the mounted end of the grip part. If the mounted end is provided with a semicircular rounded front edge section having a radius of half the breadth of the grip part that merges into the parallel side edges of the grip part, this condition is fulfilled. Thus the depth of the front leg (up to the corner of the receiving shaft) can be constant over its entire length.
If the breadth of the grip part matches the blank of the shank part, both legs of the receiving shaft, viewed over their length, can have an identical, constant shaft cross-section.
The corner of the housing through which the receiving shaft passes as well as the other outer corners and outer edges of the housing should be rounded off in such a way that they are convenient to grip in order to avoid injuries or damage. Accordingly, a corner of the flat key is adapted to correspond to the path of the corner curvature of the key case and is of constant breadth. Hence the flat key remains torsionally rigid in its transition area from the grip part to the shank part. The outer edge curvature of the key should correspond to half the breadth of the shank part.
The flat key, like a conventional flat key, is preferably of one-piece design, as a result of which its blank is inexpensive to produce.
When the key case is combined with a transmitter housing which has a signal emitting device with directional effect it is possible to have the signal emitting direction correspond to the key insertion direction. The gripping position of a user's operating hand (holding the key case) can thereby stay the same irrespective of the type of operation (key or transmitter).
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawing.